I'm sorry you had this problem, and am so glad it worked out all right, but I also learned a valuable lesson. Don't put the loose screws on the bed of the machine! I have a Janome MC9700, and it has screws, which I haven't taken out yet because I haven't had it long enough, but I feel certain I would have just put those screws on the bed of the machine. Sounds like something I would do, not thinking. So now I know not to do that, and if ever it should happen, what I can do to fix it before I resort to a repairman (always expensive!).
So your little mishap taught me a valuable lesson --- me, and who knows how many other sewers and quilters, and not just those with Janomes. I'll bet anyone with screw plates who reads this entry never puts their screws on the bed of the machine again.
Thank you for your valuable insight and information. You've helped a lot of people today.